Francium, 87FrFrancium |
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Pronunciation | (FRAN-see-əm) |
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Mass number | [223] |
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Francium in the periodic cairt |
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Atomic nummer (Z) | 87 |
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Group | group 1 (alkali metals) |
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Period | period 7 |
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Block | s-block |
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Element category | Alkali metal |
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Electron confeeguration | [Rn] 7s1 |
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Electrons per shell | 2, 8, 18, 32, 18, 8, 1 |
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Pheesical properties |
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Phase at STP | solit presumably |
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Meltin pynt | ? 300 K (27 °C, 80 °F) |
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Bylin pynt | ? 950 K (677 °C, 1250 °F) |
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Density (near r.t.) | 1.87 g/cm3 (extrapolatit) |
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Heat o fusion | ca. 2 kJ/mol |
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Heat o vapourisation | ca. 65 kJ/mol |
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Vapour pressur (extrapolatit)
P (Pa)
|
1
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10
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100
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1 k
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10 k
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100 k
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at T (K)
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404
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454
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519
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608
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738
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946
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Atomic properties |
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Oxidation states | +1 strangly basic |
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Electronegativity | Pauling scale: 0.7 |
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Ionisation energies | |
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Covalent radius | 260 pm (extrapolatit) |
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Van der Waals radius | 348 pm (extrapolatit) |
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Ither properties |
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Creestal structur | body-centred cubic (extrapolatit) |
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Thermal conductivity | 15 W/(m·K) (extrapolatit) |
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Electrical resistivity | 3 µΩ·m (calculatit) |
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Magnetic orderin | Paramagnetic |
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CAS Nummer | 7440-73-5 |
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History |
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Namin | efter Fraunce, homeland o the discoverer |
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Diskivery an first isolation | Marguerite Perey (1939) |
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Main isotopes o francium |
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| references |
style="text-align:left"|
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in
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calc from C
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diff
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report
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ref
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C
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27
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—
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—
|
|
|
K
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300
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300
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0
|
|
|
F
|
80
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81
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-1
|
delta
|
|
WD
|
String Module Error: Target string is empty !
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|
|
|
input
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C: 27, K: ? 300, F: 80
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comment
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style="text-align:left"|
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|
in
|
calc from C
|
diff
|
report
|
ref
|
C
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677
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—
|
—
|
|
|
K
|
950
|
950
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0
|
|
|
F
|
1250
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1251
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-1
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delta
|
|
WD
|
String Module Error: Target string is empty !
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|
|
|
input
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C: 677, K: ? 950, F: 1250
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comment
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References
Thir references will appear in the airticle, but this list appears anerly on this page.
- ↑ ISOLDE Collaboration, J. Phys. B 23, 3511 (1990) (PDF online)